Pixel driving circuit, display device and pixel driving method
Embodiments of the present disclosure provide a pixel driving circuit and a pixel driving method. The pixel driving circuit comprises a driving transistor, a storage capacitor, a light-emitting device, a first switch transistor, a second switch transistor, a third switch transistor, a fourth switch transistor and a fifth switch transistor. The pixel driving circuit and the pixel driving method are implemented such that a driving current generated by the driving transistor is relevant to a working voltage provided by a first power supply terminal, an activation voltage of the light-emitting device, a working voltage of the light-emitting device upon emitting light and a data voltage, yet irrelevant to a threshold voltage of the driving transistor, thereby refraining the driving current flowing through the light-emitting device from influence exerted by the non-uniformity and drifting of the threshold voltage of the driving transistor, and in turn effectively improving the uniformity of the driving current flowing through the light-emitting device.
1. A method of driving a pixel driving circuit, the pixel driving circuit comprising a driving transistor, a storage capacitor, a light-emitting device, a first switch transistor, a second switch transistor, a third switch transistor, a fourth switch transistor and a fifth switch transistor, wherein
a control electrode of the first switch transistor is connected with a second scanning line, a first electrode of the first switch transistor is connected with a first power supply terminal, and a second electrode of the first switch transistor is connected with a first terminal of the storage capacitor;
a control electrode of the second switch transistor is connected with a third scanning line, a first electrode of the second switch transistor is connected with the first power supply terminal, and a second electrode of the second switch transistor is connected with a first electrode of the driving transistor and a first electrode of the third switch transistor;
a control electrode of the third switch transistor is connected with a first scanning line, the first electrode of the third switch transistor is connected with the first electrode of the driving transistor, and a second electrode of the third switch transistor is connected with a control electrode of the driving transistor and a second terminal of the storage capacitor;
a control electrode of the fourth switch transistor is connected with the first scanning line, a first electrode of the fourth switch transistor is connected with a data line, and a second electrode of the fourth switch transistor is connected with the first terminal of the storage capacitor;
a control electrode of the fifth switch transistor is connected with a fourth scanning line, a first electrode of the fifth switch transistor is connected with a second electrode of the driving transistor, and a second electrode of the fifth switch transistor is connected with a first terminal of the light-emitting device;
the second terminal of the storage capacitor is connected with the control electrode of the driving transistor, and a second terminal of the light-emitting device is connected with a second power supply terminal; and
the first power supply terminal is used to provide a working voltage, and the second power supply terminal is used to provide a reference voltage,
the method comprising:
performing a data write phase in which the first switch transistor and the fifth switch transistor are turned off, the second switch transistor, the third switch transistor and the fourth switch transistor are turned on, a data voltage on the data line is written to the first terminal of the storage capacitor through the fourth switch transistor, and the working voltage provided by the first power supply terminal is written to the second terminal of the storage capacitor through the second switch transistor and the third switch transistor,
performing a compensation write phase in which the first switch transistor and the second switch transistor are turned off, the third switch transistor, the fourth switch transistor and the fifth switch transistor are turned on, and the driving transistor discharges to write a compensation voltage including a threshold voltage of the driving transistor to the second terminal of the storage capacitor; and
performing a display phase in which the third switch transistor and the fourth switch transistor are turned off, the first switch transistor, the second switch transistor and the fifth switch transistor are turned on, the working voltage provided by the first power supply terminal is written to the first terminal of the storage capacitor through the first switch transistor, a control voltage is output from the second terminal of the storage capacitor to the driving transistor, and the driving transistor generates a driving current under control of the control voltage to drive the light-emitting device to emit light.
2. The method of claim 1 , wherein each of the driving transistor, the first switch transistor, the second switch transistor, the third switch transistor, the fourth switch transistor and the fifth switch transistor is selected from the group consisting of a polycrystalline silicon thin film transistor, a noncrystalline silicon thin film transistor, an oxide thin film transistor and an organic thin film transistor.
3. The method of claim 1 , wherein the driving transistor is an N-type thin film transistor.
4. The method of claim 3 , wherein the first switch transistor, the second switch transistor, the third switch transistor, the fourth switch transistor and the fifth switch transistor each are an N-type thin film transistor.
5. The method of claim 3 , wherein the first switch transistor is a P-type thin film transistor, the second switch transistor, the third switch transistor, the fourth switch transistor and the fifth switch transistor each are an N-type thin film transistor, and the first scanning line and the second scanning line are the same scanning line.